1. Field of the Invention
The present invention relates to an organic light emitting display (OLED) and method of fabricating the same and, more particularly, to an OLED and method of fabricating the same, which can simplify the fabricating process by automatically patterning a pixel electrode.
2. Discussion of the Background
In general, an OLED is a self-emissive display in which light is emitted by exciting fluorescent organic compounds. The OLED can be classified into a passive matrix OLED (PMOLED) and an active matrix OLED (AMOLED) according to a driving method of N×M pixels, which are arranged in a matrix shape. In comparison with the PMOLED, the AMOLED is suitable for large-area displays due to its low power consumption and has high resolution.
In another approach, the OLED can be classified into a top-emitting OLED, a bottom-emitting OLED and a double-sided emitting OLED based on the direction in which light is emitted from organic compounds. Unlike the bottom-emitting OLED, the top-emitting OLED is a display in which light is emitted in an opposite direction to a substrate on which unit pixels are arranged and has an advantage of a high aperture ratio.
As described above, the OLED is a self-emissive display and thus requires no additional light sources. However, in order to improve luminous efficiency, some OLEDs may use as a light source by reflecting external light using a reflective layer formed of a metal with excellent reflective properties.
In the conventional OLED, when the reflective layer is formed of Al, while the reflective layer and a thin layer for the pixel electrode are being patterned at the same time, both of them are exposed to an electrolytic solution used for photolithography and etching processes. Thus, a material having a greater electromotive force corrodes due to galvanic corrosion, thereby damaging the pixel electrode. To overcome this problem, in another conventional method, the reflective layer and the thin layer for the pixel electrode are separately patterned using different photolithography and etching processes. However, in this case, the number of photolithography and etching processes is increased so that the entire fabrication process is more complicated, thereby causing a drop in yield and increasing the production cost.